Health & Environment: ...And Then How Cold?

Warming may affect sea currents, triggering an ice age

It seems obvious that trapping more of the sun's heat will make the planet hotter. But what seems obvious isn't always true. According to some respected scientists, there's a chance that global warming could plunge us into, of all things, an ice age.

The argument hinges on the Gulf Stream, the ocean current that brings warm surface water north and east and heats Europe. As it travels, some of the water evaporates; what's left is saltier and thus denser. Eventually the dense surface water sinks to the sea bottom, where it flows back southward. And then, near the equator, warm, fresh...

Want the full story?

Subscribe Now


Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!